Fix Bluetooth audio issues on macOS Big Sur
I had all manners of issues that I couldn't figure out after trawling through Console.app logs:
- 3+ seconds of latency between hitting a play button and hearing audio
- Beach-balling when opening Zoom preferences
- Latency between pressing volume up/down keys and OS response
Intriguingly, some issues disappeared when connection was established / audio was playing, so as a temporary workaround I kept John Cage on repeat in QuickTime.
The solution: rm -r /Library/Audio/Plug-Ins/HAL/ACE.driver and restart. I had it from Rogue Amoeba's Audio Hijack; they're a great crew and I trust their kit, but for whatever reason this caused issues.